Running Multiple Compressors In A Forced-Induction Application Is Not Uncommon. Multiple Symmetrical Turbos Can Be An Option On Really Big Engines, When One Turbo Just Won't Pump Enough Air. On ...

The quick and short answer to whether twin turbos hurt gas mileage is no. As for whether they help with efficiency — again, the simple answer, mind you, is yes. As you may have imagined by now, things ...